Dredging-machine



(N0 Model.) 3 sheets -Sheet 1. I. B. BARROWS. DREDGING MACHINE.

Patented Jan. '7; 1896.

WITNESSES AIM 15M". HMOMWAINIIINIJB.

(No Model.)

7 3 SheetsSheet 2. IE. 3. BARROWS.

DREDGING MACHINE. No. 552,810. Patented Jan. 7, 1896.

WITNESSES INVENTOR %ZZ M (N0 Modem 3 Sheets-Sheet a. F. B. BARROWS. DREDGING MACHINE.

No. 552,810. Patented Jan. 7, 1896.

72 Z 2% /%M z /y Wm: ESSES I a I y M M, PNGTG-LXYHQWASIHNGTON DC.

UNITED STATES PATENT EEicE.

FRED l3. BARRO\VS, OF DULUTH, MINNESOTA.

DREDGlNG-MACHINE.

SPECIFICATION forming part of Letters Patent No. 552,810, dated January *7, 1896.

Application filed 3.11118 3, 1895- .To oLZZ whom it may concern:

Be it known that I, FEED B. BARRows, a citizen of the United States, residing at Duluth, in the county of St. Louis and State of Minnesota, have invented certain new and useful Improvements in Dredging-Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in dredgers, and has particular relation to the class of dredgers known as clam-shell dredgers.

It also consists of the combination, with the main frame, of rotary shafts mounted in the same, shells or scoops mounted on said shafts, operating-levers loosely mounted on said shafts, clutches connecting said levers and shafts whereby the former may be thrown in or out of engagement with the shafts at will, and means for operating said levers.

It also consists of the combination, with the main frame, of rotary shafts mounted in the same, shells or scoops mounted on said shafts, operatinglevers loosely mounted on said shafts, shifting clutches between said levers and shafts, and a movable lifting-beam connected to said levers whereby the latter will be operated and the scoops closed together when the power is exerted upon the liftingbeam.

It also consists of certain other novel constructions, combinations, and arrangements of parts, all of which will be hereinafter more particularly set forth and claimed.

In the accompanying drawings, forming part of this specification, Figure 1 embraces a front elevation of the devices embodying my invention. Fig. 2 represents a rear elevation of the same. Fig. 3 represents a top plan view, partly in section, of said devices; and Fig. at represents a side elevation of said devices.

A in the drawings represents the main frame, which is preferably made of two castings bolted together, as at a. Each of these castings is provided with internal vertical guides a, said guides being exactly opposite each other when the two sections of the frame are secured together.

A lifting-beam B is $eria1 No. 551,510. (No modeld mounted in these guides so as to be capable of sliding vertically therein and is provided at its upper end with a lifting-sheave b suitably mounted thereon. The lower portion of the beam is bifurcated, as at b, and the opposing faces of said bifurcated portions are each provided with a circular boss or flange b the use of which will be hereinafter set forth.

Operating-shafts C are mounted in j ournalboxes a, formed upon the opposite lower ends of the frame. The shells or scoops D, which are preferably quarter-cylindrical in shape, with the flat sides open, are mounted on said shafts C by castings d, which are bolted to said scoops and keyed on the respective ends of said shafts. The said scoops or shells are so mounted in relation to each other that their vertical edges meet when in their closed position and thus form a semicylindrical receptacle closed at both ends. It will thus be seen that the rotation of the shafts will cause either the opening or closing of the scoops, according to the direction of such rotation. The shafts are rotated by means of levers E, mounted on the same, cogged levers F, connected to said latter levers, and links F, connecting said cogged levers and the liftin beam. The levers E are loosely mounted on their respective shafts and are each provided with rack-faces 6, each of which forms one member of a clutch. The other member of each clutch is a sleeve e, keyed to its respective shaft so as to rotate therewith, but being capable of longitudinal movement thereon. Each of these sleeves is provided with a rackface c adapted to engage the rack-face 6 when said sleeve is forced against the same and thus lock the shaft and the lever E together. Each of these sleeves is also provided with an annular groove 6 adapted to receive an operating-yoke G, formed on a lever G, which is pivoted to a projection g on frame A. Each of these levers is operated by a toggle-link H, one arm h of which is pivoted to said lever and an actuating-rod 11 and the other to said rod and a lug h, formed on a stop projection I of the box o The rod H passes through a lug 7L2, mounted 011 the frame A, a spiral spring its surrounding said rod and bearing against said lug and the head of said rod, so that the toggle-links are normally depressed, which causes the yoke to normally hold the racks on the sliding sleeves in engagement with the racks on the levers E.

The rods II are each connected to an operating-lever L, pivoted to frame A at a by links Z l, which are pivotally attached to the ends of said rods and said levers. Each of said links is provided with a turnbuckle m, and has a slotted end on, through which the bolt attaching it to the lever passes, whereby said links can be adjusted. The link Z is attached to the lever L above its pivotal point a and the link Z is attached to an arm extension Z at the end of said lever below its journal a.

It will be seen from the aforegoing that a movement of the lever L to the right will opcrate the links Z l and the toggles l-I, thereby releasing the clutches and allowing the shafts to turn and scoops to open independently of the movement of the levers E and the liftingbeam. The lever L is returned to its normal position by a spiral spring Z which is attached to the frame A and said lever, a stop Z on said frame limiting the movement of the same.

The outer end of each of the cogged levers F is bifurcated to receive the ends of its respective lever E to which it is pivoted. The inner segmental peripheries of said levers F are provided with cog-teeth f, said cogs being adapted to mesh with each other when said levers are operated, so that both sides of the apparatus must move together and in unison. The four links F are connected respectively to the lifting-beam B and the levers F on opposite sides of the same. The said levers F are each provided with a pair of inclined flanges f, arranged on opposite sides of the same. hen the lifting-beam is lowered, the cog portions of the levers pass between the bifurcated end of the same and the inclined flanges f engage the circular flanges Z2 thus holding the apparatus truly centered. If the device were not thus centered when open a blow on one or the other of the open shells would force the whole operating mechanism out of a true center either to one side or the other.

Each of the shafts C is provided with a flanged brake-wheel O keyed rigidly thereto. Band-brakes a, each having one end secured to a projection on frame A, pass about said wheel and are each connected by bell-crank levers c c and connecting-rod e c with a lever 0 pivoted on the frame. Said levers c are so situated that their free ends are engaged by projections b on the lifting-beam when the latter is in its raised position. These projections lift the outer ends of the said levers and apply the brakes through the medium of the bell-crank levers and connectingrods, so that when the scoops are released and start to open they are restrained by said brakes and thus open gradually and without any shock, the load gradually discharging from the same.

The operation of my dredger is as follows: The shells are first opened by operating the lever L and releasing the clutches. The whole apparatus is then lowered onto the pile or river-bed to be dredged and the weight of the apparatus forces the open shells into the sand or mud. As the tackle supporting the liftingbeam continues to descend after the shells have touched bottom, the links F force the levers F down in the center and depress the upper ends of the levers E, as shown in Fig. 1, the rack-faces of the clutches in the meantime riding over each other, as this direction of rotation imparted to them by the said 10- vers E is the one in which said rack-faces do not engage but slide smoothly one over the other. The lifting-tackle is then tightened. and as the liftingbeam ascends it carries the cogged levers F with it, with the result that the levers E are forced into an approximately allowing the scoops to slowly open against the action of the band-brakes and deposit their load. The operation is then repeated as before.

Having now described my invention, what I claim as new, and desire to secure byLettei-s Patent, is

1. In a dredger, the combination with a main frame, of rotary shafts mounted in the same. shells or scoops mounted on said shafts, operating levers loosely mounted on said shafts. clutches connecting said levers and shafts. whereby the former may be thrown into or out of engagement with the shafts at will, and means for operating said levers, substantially as described.

2. In a dredger, the combination with the main frame, of rotary shafts mounted in the same, shells orscoops mounted on said shafts. operating levers loosely mounted on said shafts, shifting clutches between said levers and shafts and a movable lifting beam connected to said levers whereby the latter will be operated and the scoops closed together upon power being applied to the lifting beam. substantially as described.

3. In a dredger,the combination with a main frame, of shells or scoops pivotally mounted thereon, a movable lifting beam connected to said scoops whereby they are closed-upon lifting power being applied to said beam, means for opening the scoops independently of the movements of said beam, and brakes con.- nected to said scoops for regulating the speed with which they open, substantially as described.

4:. In a dredger,the combination with a main frame, of rotary shafts mounted in the same, shells or scoops rigidly mounted on said shafts. operating levers loosely mounted on said shafts, longitudinally sliding clutches keyed to said shafts so as to rotate therewith, alever for operating said clutches simultaneously, and means connecting the loosely mounted operating levers with the lifting rope whereby said levers are operated when said rope is tightened, substantially as described.

5. In a dredger,the combination with a main frame, of rotary shafts mounted in the same, shells or scoops mounted on said shafts, operating levers loosely mounted on said shafts, clutches connecting said levers and shafts, intermeshin g cogged levers connected to said operating levers, a vertically movable lifting beam and links connecting said beam and said cogged levers, substantially as described.

6. In a dredger, the combination with a main frame, of rotary shafts mounted in the same, shells or scoops mounted on said shafts, operating lovers loosely mounted on said shafts, clutches connecting said levers and shafts whereby the former may be thrown into or out of engagement with the latter, intermeshing cogged levers connected to said operating levers, a vertically movable lifting beam connected to said cogged levers, hand brake wheels on said shafts, band brakes passing about the same and a lever for operating said brakes, substantially as described.

7. In a dredger,the combination with a main frame, of rotary shafts mounted in the same, shells or scoops mounted on said shafts, operatinglevers loosely mounted on said shafts, longitudinally sliding clutches connecting said levers and shafts and each having an annular groove, levers having yokes engaging said grooves, toggle links for operating said levers, and a pivoted lever for simultaneously operating said toggle links, substantially as described.

In testimony whereof I hereunto aflix my signature in presence of two witnesses.

FRED B. BARROWS.

\Vitnesses:

JAMES T. WATsoN, E. W. BARKER. 

